


Papy knows best

by damnedxfate



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, Bodily Fluids, Bondage, Ecto-Genitalia (Undertale), Ecto-Tongue (Undertale), Fontcest, M/M, Overstimulation, Punishment, Swapcest - Freeform, Underswap Papyrus, Underswap Sans, Vibrators
Language: English
Status: Completed
Published: 2017-05-06
Updated: 2017-05-06
Packaged: 2018-10-28 21:38:13
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 610
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10839951
Author URL: https://archiveofourown.org/users/damnedxfate/pseuds/damnedxfate
Summary: Sans is always so worried about others he doesn't take care of himself. But how do you punish someone with one hp? Papyrus knows.





	Papy knows best

**Author's Note:**

> SMUT!! how to?? im so sorry ive never really written smut and i hope you like it! please leave a comment or kudos if you can it helps encourage me.

Sans knew he messed up. Today was training with Alphys ONLY since there was a scheduled storm in Snowdin. Papy told him to come straight home afterward but as a future Royal guard member he had to ensure that all citizens made it home safely, even if it left him struggling to get home in the middle of said storm. By the time Papyrus found him his HP had dropped by 0.3 points and he was lost.

Papyrus was so angry! His eye was glowing and he didn't say anything to Sans just short-cutted them home and began walking to their "Room" Since he and Papyrus became a couple they slept in one room and converted the other into a playroom.

He knew he deserved any punishment he got but this was cruel! Tied with his limbs to each corner of the bed, blindfolded and gagged, Sans could barely think. Papy was so disappointed! He left him alone on the bed and he couldn't come! At the base of his dick was something Papyrus only brought out when Sans misbehaved, a small collar like ring was pulled tight to his base. Tight was the word to! Sans would of been fine with that if it wasn't for the vibrators on his sacrum, sternum and ribs! The worst part was Papyrus put the "Special" Dildo inside his butt! It was so big, with bumps going down the side and the settings! Papy had this dildo Custom made, it had 6 different levels of vibration and another setting that caused the bumps to move and vibrate separately.

The worst part was that Sans could feel Papyrus's disappointed gaze on his shameful display, this was a punishment but it felt so good. The dildo was so deep and it filled him so much. He wanted his big brother though, brothers cock was the best! Every time Papyrus fucked him his magic felt like it was gonna burst he was so stretched and his thick cum inside him was so warm. he loved laying there afterward feeling his brothers cum leaking out of him slowly. He wanted his brother now! Papy wouldn't be able to understand him through the gag so he was gonna beg him with his body then, anything! He didn't care how lewd he looked he just wanted his Papy on him, in him, forgiving him. He was so sorry!

Crying now Sans tried to thrust his hips up and call for his brother through the gag. Eventually he felt like crying harder was Papyrus truly so mad at him he thought when he felt a hand press gently on his sternum and push him down onto the bed. "I hear you bro, but are you going to listen? Will you start taking care of yourself from now on? Its ok to help others your to much of a good soul not to, but you need to take care of yourself. your so important to me little bro" was softly whispered near his face. He nodded his head frantically! Anything, he would do anything to make his brother forgive him! Anything to stop this torture. Feeling the toy being pulled out Sans didn't have a moment to complain as he was forced open wider by his brother not a moment later. Near screaming Sans surrendered himself to his brother fully. All would be well and forgiven, he wouldn't mind spending the rest of this storm tied to the bed, fucked open and filled with his brothers cum. Let it be known that Sans was a monster of his word but perhaps he needed to reminded every once and a while.

**Author's Note:**

> i hope you enjoy it im sorry ive never really written smut before. Underswap Paps is the big bro in my US headcanon. follow me on tumblr! im called DamnedXFate there to. please no minors do not follow me if you are below the age of 18.


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